It is known in the prior art to provide packages with identification codes, e.g. for identifying a particular location on the package or for identifying an individual package. One type of identification code is the optical code, usually a bar code. Bar codes can be printed on the package material along with the decor. A disadvantage in connection with bar codes is that optical vision is needed for reading the code. Therefore, the bar code has to be visible on the package and must not be covered by, e.g., a protective film. Another disadvantage is that the bar code is static and cannot be changed once it has been printed. Further, the bar code may be considered a disturbing element in the design of the package.
Another type of identification code is RFID, which uses transponders communicating via radio frequency. RFID codes can be read without direct optical vision and at a distance. However, they are undesirably expensive for many package applications. An aluminium layer in the packaging material, such as in aseptic packaging for non-refrigerated products, may inconveniently interfere with the RFID code. The RFID code may also be sensitive to certain products contained in the package.
Recently, a new packaging laminate has been developed, which is described in WO 03/095198. This packaging laminate contains magnetisable particles in at least one of its layers. The magnetisable particles have been used for marking a single point on the packaging laminate in order to facilitate printing in register with crease lines on the packaging laminate.